What is Spinal Muscular Atrophy (SMA)?

What is Spinal Muscular Atrophy (SMA)?

I’ll try to explain what SMA is as simply but holistically as I can. It can be quite complicated to really understand but I’ll do my best:

Do you remember the world-wide ice bucket challenge? Where people around the world were throwing a bucket of ice water over them to raise awareness and money for Amyotrophic Lateral Sclerosis (ALS) which is a motor neuron disease, made ‘famous’ by Stephen Hawkings. Motor neurons control the muscles that allow us to move, speak, breathe and swallow. With motor neuron disease muscles weaken, waste away and die. Motor neurons exist in the brain and the spinal cord.

SMA, or Werdnig Hoffmann disease, is a form of neuron disease. It affects the lower motor neurons which are located in the spinal cord. The motor neurons don’t send the messages properly to the muscles meaning that the person loses the abilities to move. There muscles slowly waste away due to inactivity. The muscles closest to the trunk are the first to be affected, the upper arms, shoulders, hips, back and upper legs. Next the person starts to struggle to swallow making eating difficult. They struggle to cough and cannot move any mucus from their chest, so colds are a serious issue. Eventually the person loses the ability to breath. They become trapped inside their bodies.

It is the cruelest, most devastating disease. Both to experience and to watch.

The feelings and sensations of an SMA baby are not affected, they can feel tickles, hugs and the air on their skin. Their intellect is not affected at all, in fact most people with SMA are thought to have a higher intelligence, are bright and sociable. A baby with SMA is bright, intellectual and you can see so much expression and emotion through their eyes.

There are a number of ‘types’ of SMA, which range based on age of onset and the rate of progression.

Type 0 is rare and severe, most babies born with type 0 die upon birth or in the first month or two of life.

Type 1 is what Mackenzie had. It is the most common type and is severe and lethal. Babies born with type 1 are usually diagnosed before 6 months old. The average life expectancy is 8 months old and most will pass away by 2 years old unless intervention is given. Intervention includes feeding tubes, breathing tubes or trial medications used to delay the onset of symptoms.

Type 2 are diagnosed between 6 and 18 months of age. It varies in symptoms & severity but usually children can sit but cannot walk or stand. That are prone to severe chest infections. They usually pass away by early adolescence.

Type 3 are diagnosed between 2 and 17 years old. It varies in symptoms and severity but usually it results in difficulty climbing, running and gives a tremor. People can live a full life with therapy and treatment.

Type 4 is an adult onset and can lead to tremor and difficulty moving.

I haven’t really seen many people with type 0, 3 or 4. Type 1 is the most common with type 2 the next.

SMA type 1 is a cruel, horrific, unfair, devastating condition. It is so wrong to see a baby waste away and suffer. I believe all forms of SMA are cruel and horrible but there is a range, some live full lives and can contribute to society. I find it hard to discuss SMA without hurting people who have lived with a form of it or who have a loved one who has lived with it. So, I try not to comment on anything other than our own journey with SMA as every story is different, every journey is different. But what I do know is that our journey with SMA type 1 was soul destroying.

We learnt that SMA is the number one genetic killer in babies under two. Despite this huge fact, it is largely unknown amongst society and even health care professionals.  We can only assume this is because babies tend pass away so young and those with SMA automatically are referred to specialists meaning most general Practitioners (GPs) don’t regularly look after those affected by SMA.

SMA is recessive genetic disorder which meant that it is disorder carried within her DNA which she had inherited from us. Jonny and I had no idea that we were both carriers of SMA and we had inadvertently passed this horrible condition on to her.

What is a Genetic Condition?

What is a Genetic Condition?